In other words, artificial sweeteners allow people to stick to a good diet for a longer period of time, she says. In a diet, artificial sweeteners are considered "free foods." The sugar substitutes don't count as a carbohydrate, a fat, or any other exchange.
"These products can be useful when used appropriately for people like diabetics who need to control their sugar intake and in overweight people," agrees Ruth Kava, PhD, RD, director of nutrition for the American Council on Science and Health (ACSH) in New York City.
Artificial sweeteners do not affect blood sugar levels, but some foods containing artificial sweeteners can still affect blood sugar because of other carbohydrates or proteins in these foods. In other words, while foods that contain artificial sweeteners may be sugar-free, they may not be carbohydrate-free.
Just because a food contains artificial sweeteners instead of sugar is not carte blanche for grazing, Kava points out.
"The real key to weight loss is calories," Kava points out. "If you substitute a diet soda for a sugar soda, you save 100 calories, but if you eat 15 sugar-free cookies [which have calories] instead of two regular cookies, you may not be helping yourself at all," she says.
"If somebody is trying to lose weight and cut back on calories, artificial sweeteners can add flavor to unsweetened beverages or other products," says Michael F. Jacobson, PhD, executive director of the Center for Science in the Public Interest (CSPI) in Washington. That said, "somebody who consumes a lot of artificially sweetened foods should think twice about their diet and ought to be eating real food," he tells WebMD.
"I don't think [artificial sweeteners] are needed at all," he says. "I fear that in some cases people have a diet soda for lunch and then have a couple of tablespoons of ice cream -- giving up the saved calories," he says.
Using sugar substitutes instead of sugar can lower your risk of tooth decay, but "the acid in diet soda still could contribute to dental erosion," Jacobson points out.